Snap action valve

ABSTRACT

A snap action valve mechanism includes a spool to which is coupled a magnetizable piston. A permanent magnet in a control chamber holds the spool in a first configuration. A pneumatic fluid is applied to the control chamber to act upon the piston, forcing the spool to snap into the second configuration.

United States Patent 11 1 3,722,850

Kemper 1 Mar. 27, 1973 s41 SNAP ACTION VALVE References Cited [75] Inventor: James M. Kemper, Hollywood, UNITED STATES PATENTS f 2,960,971 11 1960 Tear .Q. ..2s1 7s x [73] Assignee: Monogram Industries, Inc, Los An- 2,558,652 6 1951 lves ..251/50 geles, Calif. 2,232,538 2/1941 Kriese et al ..25l/50 1,887,078 11 1932 Wheaton ..2s1 4s [221 Flled 1970 2,306,029 12/1942 Salzer ..251/75 x [21] Appl. No.: 89,376 Y Primary Examiner-Arnold Rosenthal Attorney-Leonard Golove et al. Related U.S. Application Data [60] Division of Ser.'No. 829,486, June 2, 1969, which is [57] ABSTRACT 'i of 737,232 June 14, A snap action valve mechanism includes a spool to 1963' abandoned which is coupled a magnetizable piston. A permanent magnet in a control chamber holds the spool in a first 2% configuration. A pneumatic fluid is applied to the cong g g 251/50 75 65 52 trol chamber to act upon the piston, forcing the spool to snap into the second configuration.

4 Claims, 8 Drawing Figures AIR Patented March 27, 1973 I2 Fig l.

Toilet Flush line Storage 10 Pump TOOK 4 Filter Source Flg. 2.

AIR 06 N H8 IOO IIO II6 James M. Kemper,

INVENTOR.

SNAP ACTION VALVE The present invention relates to a snap action value, is a divisional application of application Ser. No. 829,486, filed June 2, l969, which was a continuationin-part of the application filed June 14, 1966, Ser. No. 737,232, now abandoned.

In the preferred embodiment of the parent application, the pneumatic system drives the diaphragm pump and a novel, pneumatic time delay apparatus is provided to permit a complete cycle of operation to be triggered by the momentary actuation of a push button or other start mechanism.

The novel features which are believed to be characteristic of the invention, both as to organization and method of operation, together with further objects and advantages thereof will be better understood from the following description considered in connection with the accompanying drawings in which a preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose-of illustration and description only and are not intended as a definition of the limits of the invention.

FIG. 1 is an overall block diagram of a recirculating sanitary system in which the present invention is useful; and

FIG. 2 is a side sectional view of a pneumatic snap action trigger valve combination.

Turning first to FIG 1, there is shown, in generalized diagramatic form, the recirculating sanitary system acan air supply chamber 122 in a first and second configuration, respectively. An iron piston 124 is connected to the spool valve 118 and cooperates with a permanent magnet 126 in the control chamber 110 to hold the spool valve 118 in the second or operating configuration, in which the air supply is applied to the pump.

A push button-plunger 128 is mounted in the end of the valve housing 108 and, in this embodiment, is

- adapted to contact the opposite end of the spool valve cording to the present invention in which general blocks have been utilized to represent each of the elements of such a system. Basic to the system 10 is a toilet element 12 which is mounted in conjunction with storage tank 14. Aflush line 16 supplies flushing liquid to the toilet 12 and the flush liquid and waste matter exits from the toilet 12, directly into the storage tank A pump and filter combination 18 is connected to the storage tank 14 and is also connected to a source of power through an appropriate connection. The power may be electrical, hydraulic, or pneumatic, or, may be solely mechanical, depending upon the intended location and use ofthe system 10.

An appropriate trigger and timing mechanism 20 controls the application of power to the pump and filter combination 18 for a predetermined period of time. The period depends upon the intended use of the system and the volume of flushing fluid required for normal operation of the toilet 12 relative to the storage capability of the storage tank 14.

In operation, actuation of the trigger assembly 20 permits the application of power to the pump and filter combination 18 for the predetermined period of time. The pump and filter combination 18 draws and filters fluid from the storage tank 14 and pumps this fluid through the flush line 16 into the toilet 12. The fluid is then returned to the storage tank 14 for subsequent recirculation. Typically, recirculating sanitary systems 10 are utilized in mobile vehicles such as aircraft, trailers and mobile homes, busses, campers and boats.

Turning to FIG 2, there is shown an improved trigger-type valve mechanism 100 which is suitable for use as a flush valve in a sanitary system. according to the present invention. An intake port 102 is connected to a 118. A return spring 130 biases the push button 128 out of contact with the spool valve 118 and a pin 132 retains the push button 128 in the valve body 108. Normally, the spool valve 1 18 is in the first configuration shown in FIG. 7 coupling the pump to the exhaust chamber 120 which communicates to atmosphere through an adjustably controllable restriction 134.

To operate the valve assembly 100, the push button 128 is depressed, forcing the spool valve 118 into its second, flush" configuration. The piston 124 is thereby moved into operative proximity of the permanent magnet 126 which securely holds the piston and spool valve 118. Air from the supply is transmitted to the pump through the outlet port 104 and the flexible tubing 46 and a pumping cycle is initiated. The push button 128, when released, returns to its normally extended position under the force of the return spring 130.

While the full air pressure is being applied to drive the pump, the air under pressure is also applied through the tee 106 and through the controllable restriction 114 into the accumulator tank 112 which is. connected to the control chamber in which the piston 124 is being held by the permanent magnet 126. As the pressure builds in the tank 112, the pneumatic force in the control chamber 110 exerted upon the piston 124 eventually is sufficient to overcome the magnetic attraction between the piston 124 and the permanent magnet 126 at which time the piston and spool valve 118 are moved into the first or fill" configuration. Since the attractive force of a magnet is based upon an inverse cube law relationship, a force of magnitude sufficient to break the magnetic attraction between the piston and magnet is, after the piston has moved slightly, more than sufficient to drive the valve into the first configuration. It will be appreciated that once the magnetic attraction is overcome, the valve might be considered as a snap-action valve.

In the first configuration of the trigger-type valve 100, the pressure applied to the pump and the tank 112 is permitted to vent to atmosphere through the exhaust chamber 120 and the controllable restriction 134. As the pressure drops, the pump operatesin the fill portion of the cycle and filtered liquid is drawn into the driven chamber.

The operating cycle divides into a first or flush" part, during which the pump is energized to provide a flushing liquid to the toilet, and a second or fill" part, during which the pump is refilled with filteredliquid. Depending, of course, upon the air pressure of the source of compressed air, the duration of the flush" and fill" portions of the cycle are separately adjustable by adjusting the pneumatic flow through the restrictions 114 and 134. For example, the volume of flushing liquid provided the toilet can be controlled somewhat by shortening the flushing part of the cycle by admitting air to the accumulator tank 112 at a greater rate. Similarly, the time available for refilling the pump is controlled by regulating the rate of air flow through exhaust restriction 132.

The valve 100, in operation, is monostable" in that actuation of the "push button 128 causes the valve to continue to operate for a predetermined period of time whether or not the button 128 is released. The period is determined by the setting of restriction 114, after which the spool valve 118 snaps back to the stable, first configuration. As long as air under pressure is applied to the pump, air under pressure is also being applied to the piston chamber to force the valve into the first configuration. Once in the first configuration, the air pressure applied to the supply chamber 122 tends to maintain the needle valve seated in the first. configuration since a greater surface area is provided for seating the valve than on the piston side of the spool valve 118.

Thus, there have been shown and described novel pump-filter combinations especially useful in recirculating sanitary systems and incorporating a novel, snapaction,- fluid valve. Variations and modifications will occur to those skilled in the art and, accordingly, the scope of the invention should be limited only by the claims appended below:

What is claimed as new is:

l. Inv a fluid control system, a snap-action valve for returning the valve to a predetermined state after operation, comprising:

fluid supply and a utilization device;

b. a movable valve element having at least a first position and a second position, respectively connecting and disconnecting the utilization device and the supply;

c. a servo chamber in said valve body adapted to receive fluid with said valve element in a predetermined one of said first and second positions;

. piston means in said servo chamber coupled to said movable valve element and movable therewith;

e. magnetic holding means in said servo chamber including a first element mounted in said chamber and a second element connected to said piston means, one of said first and second elements being a magnet, said magnetic holdingv means being arranged to maintain said movable valve element in the predetermined one of said first and second positions; and

f. manually operable push button means for moving .said valve element into said predetermined one of said first and second positions to bring the elements of said magnetic holding means into operational lproximit whereby said valve element is manua y place in said predetermined one of said first and second positions enabling a flow of fluid to said servo chamber for actuating said piston means, thereby moving said valve element into the other of said first and second positions when the fluid force acting on said piston means is greater than the magnetic attractive force of said magnetic holding means, thereby interrupting the fluid supply to said servo chamber.

2. Apparatus as in claim 1, above, further including a controllable restriction adjacent said servo chamber for regulating the rate of fluid flow thereto.

3. Apparatus as in claim 1, above, wherein the predetermined one of said positions is the first position and said piston means are operable to move said valve element into said second position..

4. Apparatus as in claim 1, above, wherein said magnetic holding means first element is a permanent magnet. 

1. In a fluid control system, a snap-action valve for returning the valve to a predetermined state after operation, comprising: a. a valve body adapted to be connected between a fluid supply and a utilization device; b. a movable valve element having at least a first position and a second position, respectively connecting and disconnecting the utilization device and the supply; c. a servo chamber in said valve body adapted to receive fluid with said valve element in a predetermined one of said first and second positions; d. piston means in said servo chamber coupled to said movable valve element and movable therewith; e. magnetic holding means in said servo chamber including a first element mounted in said chamber and a second element connected to said piston means, one of said first and second elements being a magnet, said magnetic holding means being arranged to maintain said movable valve element in the predetermined one of said first and second positions; and f. manually operable push button means for moving said valve element into said predetermined one of said first and second positions to bring the elements of said magnetic holding means into operational proximity, whereby said valve element is manually placed in said predetermined one of said first and second positions enabling a flow of fluid to said servo chamber for actuating said piston means, thereby moving said valve element into the other of said first and second positions when the fluid force acting on said piston means is greater than the magnetic attractive force of said magnetic holding means, thereby interrupting the fluid supply to said servo chamber.
 2. Apparatus as in claim 1, above, further including a controllable restriction adjacent said servo chamber for regulating the rate of fluid flow thereto.
 3. Apparatus as in claim 1, above, wherein the predetermined one of said positions is the first position and said piston means are operable to move said valve element into said second position.
 4. Apparatus as in claim 1, above, wherein said magnetic holding means first element is a permanent magnet. 